Enhanced H-VPLS service architecture using control word

ABSTRACT

The present disclosure is generally directed to systems and methods associated with data communications. In a particular embodiment, a method for use of multi-protocol labels switching (MPLS) encapsulation with control word communicated over a distributed computer network is disclosed. The method includes providing MPLS virtual circuit label with the control word associated with a data packet selected from one of a customer data packet and an OAM data packet, and communicating the MPLS packet with control word and the data packet over the distributed computer network. 
     In another embodiment, a method of handling a data packet within a computer network is disclosed. The data packet is either an unknown unicast, multicast, or broadcast packet. The method includes encapsulating the packet into a multi-packet label switching label and a control word, the control word having a source site identity and a multi-cast identity; and distributing the packet to a plurality of sites within the computer network.

BACKGROUND

1. Field of the Invention

The present disclosure relates to Ethernet over multi-protocol labelswitching (MPLS) service.

2. Description of the Related Art

Many systems and architectures have been disclosed for handling datatraffic over distributed networks. One type of system that has beenrecently proposed to the Internet Engineering Task Force (IETF) is anEthernet over multi-protocol label switching (MPLS) architecture.

While the proposed system has many benefits in providing cost effectivedata services, this system fails to adequately take into considerationscalability issues, such as medium access control (MAC) addresscomputational concerns for networks with large numbers of customer MACaddresses, and maintenance issues, such as providing edge-to-edgetroubleshooting.

Accordingly, there is a need for improved systems and methods ofproviding Ethernet over MPLS.

SUMMARY

The present disclosure is generally directed to systems and methodsassociated with data communications. In a particular embodiment, amethod for use of multi-protocol labels switching (MPLS) encapsulationwith control word communicated over a distributed computer network isdisclosed. The method includes providing MPLS virtual circuit label withthe control word associated with a data packet selected from one of acustomer data packet and an OAM data packet, and communicating the MPLSpacket with control word and the data packet over the distributedcomputer network.

In another embodiment, a method of handling a data packet within acomputer network is disclosed. The data packet is either an unknownunicast, multicast, or broadcast packet. The method includesencapsulating the packet into a multi-packet label switching label and acontrol word, the control word having a source site identity and adestination site identity. The destination site identity could be amulti-cast identity. The packet is distributed to a plurality of sitesassociated with the customer virtual private network within the computernetwork.

In another embodiment, a method of handling a data packet within acomputer network where the destination address is known to the localnode is disclosed. The method includes encapsulating the packet into amulti-packet label switching label and a control word, the control wordhaving a source site identity and a multi-cast identity; anddistributing the packet to a plurality of sites within the computernetwork.

In another embodiment, a method of handling a data packet at ingressnode multi-tenant unit (MTU) is disclosed. The method includes receivinga data packet from a data port responsive to customer equipment;performing customer medium access control address learning; determiningwhether the data packet is a unicast packet and if the packet is unicastpacket and destination address is known to the local node, encapsulatingthe data packet into a multi-packet label switching label and a controlword. The control word has a provider source site identity and aprovider destination site identity. If the destination address of thepacket is multi-cast, broadcast or unknown unicast address, the datapacket is encapsulated into a multi-packet label switching label and acontrol word. The control word has a provider source site identity and aprovider multicast site identity.

In another embodiment, a method of handling a data packet communicationis disclosed. The method includes receiving the data packet at an egressmulti-tenant unit (MTU) port; performing a mapping between a sourcemedium access control address of the data packet and a provider sourcesite identity; removing a multi-packet label and control word from thedata packet to produce an Ethernet data packet; and sending the Ethernetdata packet to a destination site. In another embodiment, a method ofhandling a data packet communication is disclosed. The method includesreceiving the data packet at provider edge device (PE); performingprovider site ID learning; determining whether the data packet is aunicast packet; if the packet is unicast packet and destination Site-IDis known to the local node, forwarding the packet to the destination PEdevice; and if the destination Site-ID of the packet is multi-cast,broadcast or unknown unicast address, distributing the packet to aplurality of sites associated with the customer virtual private networkwithin the computer network.

In yet a further embodiment, a method of testing data communicationwithin a network is disclosed. The method includes generating a testingpacket for communication by a multi-tenant unit; and communicating thetesting packet from the multi-tenant unit to another element within thenetwork. The testing packet includes a control word. The control wordincludes a site destination identification field and a site sourceidentification field.

In another embodiment, a control word for use in connection with adistributed computer network having customer equipment at a first sitewhere the customer equipment has a plurality of associated medium accesscontrol addresses is disclosed. The control word includes a serviceprovider site identification field to represent a group of the pluralityof medium access control addresses at the first site.

In another embodiment, a distributed computer data network of a serviceprovider is disclosed. The distributed computer data network includes afirst computing node (source multi-tenant unit); a second computing node(provider edge device); a third computing node (provider edge device) afourth computing node (destination multi-tenant unit); and a data packetcommunicated between the first computing node and the second computingnode, the data packet including a control word having a providerdestination identification corresponding to the location of the fourthcomputing node. The second computing node receives the data packet andforwards the data packet to the third computing node in response toprocessing the provider destination identification to determine thepacket destination.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram that illustrates a particular systemarchitecture that provides Ethernet over IP/MPLS.

FIG. 2 illustrates an example of a customer packet that can be usedwhere the control word is defined.

FIG. 3 is a flow diagram illustrating a method of customer packethandling at an ingress MTU point using a control word mode.

FIG. 4 is a flow diagram illustrating a method for handling packets atan egress MTU point using a control word mode.

The use of the same reference symbols in different drawings indicatessimilar or identical items.

DETAILED DESCRIPTION OF THE DRAWING(S)

Referring to FIG. 1, a system 100 is disclosed. The system 100 includescustomer equipment 112, multi-tenant unit (MTU) 102, provider edgeequipment unit 106, a second provider edge equipment unit 108, internetprotocol/multi-protocol label switching core (IP/MPLS) 128, adestination multi-tenant unit 110, and destination customer equipment116. The customer equipment 112 is located at a first site and isassociated with a plurality of medium access control (MAC) addresses114. The customer equipment 112 at the first site is linked to the MTU102 via link 120. Data communicated between the CE 112 and the MTU 102is received at a first port 122 of the MTU 102. The MTU 102 includes avirtual circuit (VC) encapsulation with control word module 140 and asite identification (ID) and customer MAC mapping learning module 142.The provider edge equipment 106 includes site identification learningmodule 150 and is coupled to another MTU 104 via virtual circuit 126.The first provider edge equipment unit 106 is in communication with thefirst MTU 102 via virtual circuit 124.

The second provider edge equipment unit 108 also includes a siteidentification learning module 152 and is coupled to MTU 110 via virtualcircuit 130. The MTU 110 includes a site identification and customer MACmapping learning module 146 and VC encapsulation with control wordmodule 144. The MTU 110 is coupled to customer equipment 116 via datalink 134. The customer equipment 116 is located at a second site and isassociated with a second plurality of MAC addresses 118.

During operation, data packets originating from the customer equipment112 at the first site are communicated over data link 120 and the firstport 122 to the MTU 102. At the MTU 102, a site identification fortefirst site of the customer equipment 112 is associated with a pluralityof MAC addresses for such customer equipment. In addition, the MTU 102performs site ID and customer MAC mapping learning 142. The MTU 102communicates with the provider edge equipment 106 by sending a packetwith VC encapsulation and control word 160. The control word 160includes a source site identification (ID) and a destinationidentification (ID) associated with the first site where the customerequipment 112 is located. Similarly, the destination ID is associatedwith the destination site, such as the second site where the customerequipment 116 is located.

The provider edge equipment 106, responsive to receipt of the datapacket and control word 160, receives the site ID information, performssite ID learning via module 150, and determines the destination ID forfurther routing of the packet. Data packets are forwarded by theprovider edge equipment 106 via the IP/MPLS core network 128 to far endprovider edge equipment, such as provider edge equipment 108. Theprovider edge equipment 108 further passes a packet with VCencapsulation and control word 162 containing the destination site IDvia virtual circuit 130 to the MTU 110. The encapsulated control wordpacket and the associated data packet for the control word 144 areprocessed at the MTU 110. The site ID, destination ID, and MAC learningprocesses 146 are performed, MPLS VC label and control word are stripedoff and the packet is routed and forwarded to the customer equipment 116at the second site. Finally, the customer equipment 116 forwards thecommunicated data to the appropriate equipment based on the particulardestination MAC address.

FIG. 2 illustrates an example of a customer packet header that can beused where the control word is defined. Field 1102 is for the MPLS VClabel and is four octets. Fields 1104 and 1113 are reserved and are eacheight bits. Field 1106 is twelve bits for the destination or Multicastsite IDs. Field 1108 is for the source ID and is also twelve bits. Theillustrated data packet also includes customer destination or broadcastMAC 1110, customer MAC source address 1112, original Ethertype 1114,customer payload 1116, PAD 1118, and original FCS 1120.

Referring to FIG. 3, a method of customer packet handling at an ingresspoint MTU using a control word is illustrated. A packet is received froma customer facing port at 1404 and customer MAC learning of the packetis performed, at 1406. If the packet is determined to be a unicastpacket at decision step 1408, then a mapping of the packet destinationMAC address is located with the provider destination site ID, at 1410.If the packet is located as determined by decision step 1412, then thepacket is encapsulated into an MPLS frame, the VC label and control wordis defined with the provider source ID and destination site ID, at 1414,and the packet is forwarded to the destination site, at 1416. Referringto decision step 1408, where a packet is determined to be a multicastpacket, or in the case where decision step at 1412 is negative due tothe packet mapping not being located, then processing continues at 1418,where the packet is encapsulated into an MPLS frame, the VC label andcontrol word are populated with the provider source site ID andmulticast destination site ID, and the multicast packet is broadcast tothe entire set of VPLS sites, at 1420. In either scenario, processing isthen completed at step 1430.

Referring to FIG. 4, a method for handling packets at an egress pointMTU using a control word mode is illustrated. A packet is received at anegress port MTU, at 1504. The destination site is checked at 1506. Ifthe destination site is not equal to the multicast site ID or the portsite ID, at decision step 1506, then error handling is performed at 1512and processing is completed at 1520. If the destination site is equal tothe multicast site ID or port site ID, as determined at decision step1506, then the destination MAC is compared to the provider port MAC orthe multicast MAC, at decision step 1508. Where the destination MACequals either the provider port MAC or the multicast MAC, then OAMprocessing is performed at 1510 and the method is completed at 1520.Where the destination MAC is not equal to the provider MAC or multicastMAC, then the method performs learning and mapping between the customersource MAC and the provider site ID, at 1514, thereafter, the MPLSVC-label and control word is stripped off, and the Ethernet packet isforwarded to the customer at 1516. Processing is then completed at 1520.

The present disclosure presents a MPLS encapsulation mechanism withControl Word for providing Hierarchical-Virtual Private Local AreaNetwork Service (H-VPLS) using Ethernet over MPLS. VPLS is a class oflayer-2 virtual private network (VPN) services that allow multiplecustomer sites to be connected over a provider managed IP/MPLSinfrastructure, so that customer devices appear to be on the same LocalArea Network (LAN). The multi-tenant unit (MTU) device performs MPLS VCencapsulation and customer MAC and provider Site-ID mapping learning.

The MPLS encapsulation technique with Control Word may be used to avoidcustomer MAC handling on provider edge (PE) devices. A new providerSite-ID is provided to represent one or many customer MAC addressesbehind a customer facing port (e.g., behind a MTU). PE devices perform alimited amount of network address learning. The MPLS encapsulation withControl Word also provides for OAM delivery (e.g., to facilitatepoint-to-point, point-to-multi-point reachability testing, performancemeasurement, or the like). Customer MAC learning at gateway devices maybe beneficially reduced or eliminated when a VPLS service spans multipledomains.

The above disclosed subject matter is to be considered illustrative andthe appended claims are intended to cover all such modifications andother embodiments which fall within the true spirit and scope of thepresent invention. Thus, to the maximum extent allowed by law, the scopeof the present invention is to be determined by the broadest permissibleinterpretation of the following claims and their equivalents, and shallnot be restricted or limited by the foregoing detailed description.

1. A distributed computer data network of a service provider, thedistributed computer data network comprising: a first computing nodecomprising a source multi-tenant unit (MTU); a second computing nodecomprising a first provider edge device (PE); a third computing nodecomprising a second PE; a fourth computing node comprising a destinationMTU; wherein a data packet is communicated between the first computingnode and the second computing node, the data packet including a controlword having a provider destination identification corresponding to alocation of the fourth computing node, wherein the data packet has adestination medium access control (MAC) address; and wherein the secondcomputing node receives the data packet and forwards the data packet tothe third computing node in response to processing the providerdestination identification to determine the packet destination, andwherein operations administration and maintenance (OAM) processing isperformed when the destination MAC address equals a multicast MACaddress.
 2. The distributed computer network of claim 1, wherein thesecond computing node comprises a first provider equipment node thatincludes a first site identification learning module, and the thirdcomputing node comprises a second provider equipment node that includesa second site identification learning module.
 3. The distributedcomputer network of claim 1, wherein the first provider edge device iscoupled to the second provider edge device via an intermediate labelswitching data network.
 4. The distributed computer network of claim 1,wherein the first computing node comprises: an input interface tocustomer equipment; a virtual circuit packet encapsulation module; and acontrol word encapsulation module.
 5. The distributed computer networkof claim 4, wherein the first computing node further comprises a siteidentification and a customer medium access control mapping and learningmodule.